It is known in the art of fiber optics that a polarization preserving (or maintaining) fiber will maintain the polarization of light launched into one end such that the light exiting from an opposite end has substantially the same polarization as that which entered it. However, if an elliptically polarized or circularly polarized light enters a polarization maintaining fiber, the light that exits the fiber will be polarized along both orthogonal polarization modes corresponding to the input signal.
However, it would be desirable to obtain an optical fiber which receives randomly elliptically polarized input light and provides output light polarized only along a single polarization.
It is also known that a fiber optic amplifier may be made using polarization preserving fiber. However, such an amplifier has the same drawbacks as the aforementioned optical fiber when a randomly elliptically polarized input signal is incident thereon and the desired output signal is a singularly polarized signal.
Thus, it would be desired to provide an optical amplifier which provides an output signal polarized only along a single polarization mode.